Interesting study here on age vs mortality in motorcycle crashes. Pardon the pun in the title. Its theirs, not mine.
I suspect its not just motorcyclists who are more vulnerable as we age, but anyone in an active sport where you can bang yourself up and heal more slowly. I recently did an amusing biff on the mountainbike down in Bayo Canyon, and joked to my wife later that night, while cleaning up the wound, that it was my annual bone density exam. Fortunately, in that particular tete a tete between my forearm and Mr. Bandelier H. Tuff, neither side was bruised beyond repair. There would be far less humor if I came home in a cast.
But this paper (Univ of Rochester School of Medicine/Strong Memorial Hospital "press release" version shown in that link) suggests that as we age, we need to be more careful of consequences of being a weekend warrior. To wit, "...The increase in injury severity for older (motorcycle) riders may be related to the reduced capacity to withstand injury as the body ages. Age-related changes, such as decreases in bone strength and brain size, may make older riders more susceptible to injury. Other factors associated with aging, such as impaired vision, delayed reaction time, and altered balance contribute to motorcycle crashes in this population, explaining in part the researchers’ finding that older riders crashed more often as a result of loss of control than younger riders...."
I think fit bicycle riders have it easier in two regards. One, you are usually going slower, wide-open descents out of the Jemez Mts. on Rt 4 notwithstanding. Two, compared to those aging warriors who have taken up motorcycling after a long hiatus, an active cyclist may have preserved those critical balance and coordination skills. If he or she has been a lifelong fit adult involved in cross training, he/she may be less likely to have suffered undiagnosed bone density loss. Of critical importance is brain shrinkage in older people, which I assume makes you more susceptible to brain damage in a head impact due to the brain loosely bouncing around in the skull, thus the need to wear a helmet (and avoid...um...testing its effectiveness). Anyway, go read the original. I'm not a doctor and don't play one on TV.
This article, in part, applies especially to those who have returned to motorcycling after a long hiatus. Um...for example, me. But its good reading for anyone interested in the interplay between active lifestyles, the aging process, and injury risk.
I jogged my memory a bit and remembered that my good friend and pen-pal Maynard Hershon crashed his bicycle (not even with a car) in 2008 and blogged about it. It was a bike path crash. Maynard is a few rotations of the sun ahead of me, and his crash involved a very difficult recovery. Some of his comments here and here and a few more in between. I know some local riders who are This Side Of The Hill who have had difficult crashes, but don't want to violate anyone's confidence.
Stay fit and prosper. Keep riding,by all means, because the fun factor AND fitness factor are far too important to walk away from. Frankly, a sedentary lifestyle is far more hazardous to an old coot like me than an occasional (and minor) biff from the bike saddle. And lest Steve has to remind me, I'll remind you: cycling is fun and safe!